St Just, Cornwall

Key facts

PROJECT: St. Just

LOCATION: St. Just, Cornwall

CLIENT: Kier Living

SIZE: 36 Affordable Homes

TIMING: 8 Weeks

Type and size of project

Kier Living’s development at St Just, Cornwall, is an affordable housing project for the Sanctuary Housing Association consisting of 32 houses and four bungalows, organised in blocks of two and three terraced homes. Each was designed with the purpose of providing affordable quality by Devon architecture practice, Trewin Design Partnership.

Description of project

The site at St Just provides a much needed affordable option to an area where homes are among the fastest selling in the country.

This project represented the third successful affordable housing development that Stewart Milne Timber Systems has worked on with the main contractor Kier Living. Previously the two companies had worked on successful developments in Torquay and Paignton.

Both of these projects had to be delivered within tight budgets and extremely fast build programmes. Stewart Milne Timber Systems was therefore selected on its track record of delivery and the ability of its product range to meet the requirements of the project at hand.

Because of Sanctuary Housing’s imperative need for good quality affordable housing in the area, speed of build was integral to the project’s success and, as such, a timber frame solution was the ideal fit for its needs. A closed panel system was used to achieve this, while also delivering the energy performance and quality required for each of the homes.

To ensure success, early engagement with the design team was essential, as the timber frame was delivered to the site just six weeks after Stewart Milne Timber Systems became involved in the project. The company used its in-house design team to ensure that Kier Living’s requirements were quickly understood and all the pertinent information for the design, engineering and manufacture phases was communicated.

This meant that the homes would be designed cost effectively with enough benefits realised through offsite manufacture for follow-on trades.

With delivering to the required deadlines of the utmost importance, Stewart Milne Timber Systems erected all of the homes on site in just eight weeks using mobile cranes and two crews of erectors. This compares with the 14 – 15 weeks it would have taken if a masonry build solution had been used.

Because the project required such a speedy build, special considerations had to be given to logistics. The site was situated just five miles from Land’s End, which presented challenging access routes and the risk of overcrowding. Stewart Milne Timber Systems worked with Kier Living to overcome these potential issues through meticulous organisation of fascia and soffits deliveries to the site.

Likewise, with the site on a coastal area, it experienced strong winds. By manufacturing the panels and flooring cassettes offsite, Stewart Milne Timber System was able to limit the amount of crane lifting required. This ensured the strong coastal winds did not adversely impact the build programme.

To achieve the high standard of energy efficiency required of the project, a closed panel system was used resulting in a U-Value of 0.25 W/m2K. To ensure air loss was kept down to a minimum, the closed panel system achieved an air tightness of 4 m³/hm² @ 50 p.a.

Likewise, the external wall panels were supplied with factory-fitted mineral wool insulation, while reflective breather membranes were placed on the external face on 9mm OSB. The internal face was factory-fitted with VCL and service battens, which has the benefit of alleviating quality issues on site and also saved valuable time on the project.

The party walls were then clad with 9mm OSB boarding for the 1200mm at the beginning and end of the cavity. Meanwhile, 60mm insulation to the party wall cavity was supplied and fitted on site by the Stewart Milne Timber Systems team. The party wall internal faces were then filled with 90mm insulation and VCL, enhancing the energy efficiency of each property by excelling at the requirements for thermal bypass under Part L of the 2010 Building Regulations and enabling the party wall to achieve a U-Value of 0 W/m2K.

Working closely with Kier Living, Stewart Milne Timber Systems was able to successfully complete the project to budget and within the required time frames, despite site constraints.